The invention belongs to the technical field of drilling, tapping and milling compound machines, and particularly relates to a horizontal five-axis drilling, tapping and milling compound
machine. The five-axis drilling, tapping and milling combined
machine comprises five-axis drilling, tapping and milling
machine heads and a combined machine base connected with the bottoms of the five-axis drilling, tapping and milling machine heads, a
machining supporting table is arranged between the five-axis drilling, tapping and milling machine heads which are oppositely distributed, and a supporting bottom bin is fixedly arranged at the bottom of the
machining supporting table; the supporting extension table is attached to the side face of the
machining supporting table and the side face of the supporting bottom bin, a side
waist transverse groove is formed in the surface of the supporting bottom bin, an extension bottom rod part inserted into the side
waist transverse groove is fixedly arranged at the bottom of the supporting extension table, and a pressing mechanism acting on the extension bottom rod part is arranged in the supporting bottom bin. By means of the detachable and rotatable supporting extension table, the supporting area can be flexibly expanded according to the size of a workpiece, point-to-point precise supporting of an ultra-long workpiece and a special-shaped workpiece is achieved in cooperation with a moving block in a longitudinal groove of the extension table and a height-adjustable supporting head, and the clamping angle can be flexibly adjusted through a combined structure of an arc-shaped adjusting plate and a multi-edge transverse inserting column.